Mauro Sette

Augmented Reality for Minimally Invasive Surgery: Overview and Some Recent Advances

Pablo Lamata1,2, Wajid Ali3, Alicia Cano1, Jordi Cornella3, Jerome Declerck2, Ole J. Elle3, Adinda Freudenthal4, Hugo Furtado5, Denis Kalkofen6, Edvard Naerum3, Eigil Samset3, Patricia Sanchez-Gonzalez1, Francisco M. Sanchez-Margallo7, Dieter Schmalstieg6, Mauro Sette8, Thomas Studeli4, Jos Vander Sloten8 and Enrique J. Gomez1 1Universidad Politecnica de Madrid, Spain 2Siemens, United Kingdom 3University of Oslo, Norway 4Delft University of Technology, Netherlands 5Medical Centre Ljubljana, Slovenia 6 Graz University of Technology, Austria 7Minimally Invasive Surgery Centre Jesus Uson, Spain 8University of Leuven, Belgium

Flexible Elastoresistive Tactile Sensor for Minimally Invasive Surgery

In minimally invasive surgery, tactile feedback is lacking. An elastoresistive tactile sensor is designed to feel inside the body of the patient. The sensor is thin, flexible, robust, cheap, and has a simple structure. It has 16×16 elements, a spatial resolution of 1 mm and a bandwidth of 78 Hz. Despite a large hysteresis and non-linear behaviour, the sensor is very well suited for a qualitative measurement of the pressure distribution, with a high resolution in position, force and time.

Powerful Compact Tactile Display with Microhydraulic Actuators

In minimally invasive surgery, tactile feedback is lacking. A tactile display, consisting of a matrix of micro-actuators, represents tactile sensations on the fingertip. Miniaturising powerful, dynamic and accurate actuators with a sufficient stroke is a considerable challenge. This paper presents a proof of concept of a tactile display, based on microhydraulic actuators. A prototype with five taxels is designed, built and evaluated. The result is a light and compact display. It is mobile, has a stroke of 2 mm, a spatial resolution of 2 mm and can exert a maximal force of 0.5 N. The actuation principle is innovative in the field of tactile displays and has a great potential.

Accurate Haptic Teleoperation on Soft Tissues through Slave Friction Compensation by Impedance Reflection

Although touch clues are very important during manual surgical procedures, none of the commercial robotic tele-operation systems for soft tissue surgery offer force feedback from the slave robot to the master controller. The search for ideal telemanipulation, whereby the operator feels as if he is manipulating the remote environment directly, is often hampered by the disturbing friction forces in the slave manipulator. These mask and distort the minute interaction forces occurring during manipulation of soft tissues during surgery. In this paper, impedance reflection is put forward as a powerful means to neutralise the negative influence of disturbance forces in the slave manipulator in robotised laparoscopic surgery. Experimental evidence obtained with a Storz endoscopic robot prototype shows that almost ideal force reflection can be achieved, even in the presence of high levels of friction

P4F-3 Comparing Optimization Algorithms for the Young's Modulus Reconstruction in Ultrasound Elastography

This work compares different optimization algorithms for the solution of the inverse elasticity problem (IEP) in elastography. Five different algorithms are tested on finite elements models with different mesh sizes, where the assumptions of pure elastic behavior and linear finite elements are done. The main application of the proposed IEP algorithm for the reconstruction of Youngs modulus of soft tissues is to be used in an implementation of a haptic-tactile feedback for minimally invasive robotic surgery.

Algorithms for ultrasound elastography: a survey

Elastography is a useful and interesting technique that can be used to infer stiffness information from ultrasound medical images. In one decade of activity, the scientific community has developed this technique to a more and more mature stage, such that it has evolved into a fruitful application for clinical practice. During this decade, the evolution has proceeded from qualitative stiffness information to numerical quantification using different algorithms and approaches, based on both iterative and direct approaches. Moreover, different post- and pre-processing techniques as well as evaluation methods have been implemented. This work presents a survey on the methods developed by giving a short overview of algorithms and mathematical solutions and by analysing results and comparing methodologies.

Catheter navigation based on probabilistic fusion of electromagnetic tracking and physically-based simulation

Minimally invasive endovascular procedures including robotically assisted intervention require effective intraoperative guidance. This is mainly achieved through intraoperative imaging such as fluoroscopy. Concerns over excessive x-ray radiation and nephrotoxicity due to repeated injection of contrast agents have motivated the development of effective catheter navigation schemes based on limited imaging data. This paper presents a catheter navigation technique based on probabilistic fusion of in situ real-time electromagnetic tracking with physically-based simulation of the mechanical characteristics of the catheter. A catheter with multiple electromagnetic sensors placed along its length has been developed. The sensor data and the catheter insertion-length are used as the boundary condition for determining the shape and position of the catheter within the vasculature. A probabilistic framework based on a Kalman Filter is used to combine the information from the catheter motion algorithm and the electromagnetic tracking data. This provides continuous visualization of the catheter within the lumen without the need of continuous fluoroscopy and contrast injection. The proposed approach has been validated with detailed in vitro experiments demonstrating the potential clinical application of the technique.

Design Considerations for Lateral Skin Stretch and Perpendicular Indentation Displays to Be Used in Minimally Invasive Surgery

Despite the advantages of minimally invasive surgery the applicability of (robot assisted) minimally invasive techniques is limited to simple operations due to the lack of tactile feedback. Tactile feedback is essential in many operations such as border detection during tumor resections and localization of nerves and veins embedded in soft tissue. This work compares the performance of existing tactile stimulation methods using psychophysical techniques in an edge detection test. Several mechanical and psychophysical design considerations for lateral skin stretch and perpendicular indentation displays are given. Considering the list of disadvantages, related to lateral skin stretch, we conclude that perpendicular indentation is the preferred stimulation method for tactile feedback systems to be used in minimally invasive surgery.

Endoclamp Balloon Visualization and Automatic Placement System

OBJECTIVES Aortic occlusion is one of the most important open discussions in minimally invasive cardiac surgery. Different techniques can be employed, and all have benefits and drawbacks. The objective of our work is to improve the safety of internal aortic occlusion with the Port Access technique, which employs an endoclamp balloon catheter. We propose a combined information and positioning system based on augmented reality technology and robotics in which the position of the balloon can be seen at all times and can be automatically controlled by a robotic actuator. METHODS The system was designed by a multidisciplinary team of engineers, medical doctors, and human factor specialists in a human-centered design approach. We measure the balloon position in real time with a magnetic tracking system. This position is superimposed on a 3-dimensional scan of the patients thorax, with the balloon in the artery shown at all times. The position measurement is also used to control the robotic catheter inserter that places and maintains the balloon position at a specified target. The system was evaluated in 2 user studies that compared it with other visual aids. RESULTS The user tests have shown that the system effectively supports the surgeon in the placement task, with an increase in placement accuracy and a reduction in time compared with the current visualization technique. The users also rated the system as supporting them well. CONCLUSIONS The clinical feasibility of the system was proved. The system provides better visualization and position control and can effectively increase the safety of the procedure. This system has the potential of making Port Access a more attractive technique.

Physiological Parameters Based Control Scheme for Automatic Intravascular Balloon Inflation

A control scheme based on physiological parameters for the inflation of an intra-aortic clamping balloon is presented. Automatic volumetric pumps for the inflation of balloon catheter have been largely developed, although the process modelling for catheter mounted balloon’s inflation has never been discussed. Automatic inflation is a key issue for autonomous positioning and navigation of an intra-aortic catheter. This work explores the possibility of modelling the inflation process for a catheter mounted balloon, proposing a first order model. The pole’s position depends by the catheter’s hydraulic resistance and by the sum of the aorta’s and balloon’s compliance. Main advance of this control scheme is the fact of taking into account a physiological parameter, integrating it in the control algorithm. The estimation of the aorta’s compliance can be done either with in-vitro experiments or at the same time while controlling the pump by means of an adaptive control scheme. The scheme was applied to control a volumetric pump and tested in vitro and in vivo, showing a reasonable settling time, rise time and overshoot.